Fusible link.



L. M. LEWIS.

'FUSIBLE LINK. APPLICATION FI LED luLv zl. 1916.

WITNESS Arromisv INVEN TOR V i Z57??? era FFKQ.

NUSIBLE LINK.

Specification of Letters iatent.

Patented Oct. 23, 1917.

. Application filed July 21, 1916. Serial No. 110,449.

To all whom it may concern:

Be it known that I, LEROY M. LnwIs, a citizen of the United States, and a resident of Merion, county of Montgomery, and State of Pennsylvania, have invented certain new and useful Improvements in Fusible Links, of which the following is a specification, reference being had to the accompanying drawing.

My invention relates to fusible links of the sort more especially intended for use with automatic sprinkler heads for fire extinguishing apparatus and other devices wherein it is desired to maintain certain elements in positive relation until the temperature in the vicinity of the apparatus reaches a point sufficient to melt a fusible material normally uniting the parts of the link in assembled relation to permit the separation thereof and consequent release of the elements of the mechanism with which the link is arranged to coiiperate.

Among the principal objects of my invention are to provide a fusible link of this character which shall be positive and efficient in operation, and in which a positive and substantially instantaneous separation of the members of the link will occur when the temperature in the vicinity of the link is raised sufficiently to cause the melting of the fusible material which normally serves to secure the members in assembled relation.

Further objects of my invention are to provide a fusible link having the foregoing characteristics, which shall be of great strength, which can be readily and cheaply constructed, which shall be so designed as.

to minimize the strain upon the fusible material which serves to normally unite the members of the link, and in which relative movement or creeping of the members will not occur even though the link be kept under maximum tension for long periods of time as when used in connection with automatic sprinkler heads for fire extinguishing systems.

My invention further includes all of the various other novel objects and features of construction and arrangement hereinafter more definitely specified and described.

In the accompanying drawing is illustrated a fusible link constructed in accordance with apreferred embodiment of my invention, Figure 1 being a side elevation of the link in operative position upon fragmentary portions of the lever arms of an automatic sprinkler head; Fig. 2 a central vertical section of the link removed from the arms; Figs. 3, 4 and 5, respectively, side elevations of the several members composing the link and separated from each other, and

F igs. 6, 7 and 8, respectively, front elevasuitable fusible material or solder disposed between their adjacent surfaces.

' More specifically, each link comprises an intermediate member A" and exterior members B and C each having'a body preferably formed from suitable sheet metal or the like and providedwith suitably disposed projections or indentations arranged for engagement with corresponding indentations or projections of an adjacent member in the manner hereinafter described. Preferably the intermediate member A maycomprise a fiat substantially oblong body 1 provided with oppositely disposed projections 3 and 4, 4, the projection 3 extending outwardly from one side of the body and centrally thereof, and the projections 4, 4 extending outwardly from the other side of the body and on either side of projection 8, the combined width of all of the projections being preferably equal to that of the body portion and each projection being substantially onethird of the width thereof. The projections may be struck fromthe body or otherwise formed thereon in any desired shape or outline but may each preferably comprise two distinct sides forming substantially a right angle with each other so that the projec somewhat nearer one end of the body than.

the other and a suitable aperture 6 provided adjacent the extremity of the longer 1 end thereof, to permit the passage through the body of an arm of the sprinkler head, or the like, with which the operate, l

link is intended to oo- The members B and C are each provided with one or more indentations or depressions suitable for the receptionof 'theprojections somewhat nearer one end of the member:

than the other and equally distant from the lateral edges thereof, the width of the .in-' dent'ation being preferably substantially one-third of that of the member, and hence substantially equal to the width of the projection-3 of member A. Similarly member C is preferably provided with two suitable indentations or depressions 12, 12 corresponding to projections 4, t on member A and located one adjacent each lateral edge of the member, each indentation being substantially equal in width to one -thiid' of thewidth of the body 13 of themember and both being formed in the same surface of the body and extending in the same direction therefrom.

While the indentations or depressions in members B and C may be formed in any suitable manner to adapt them for engage ment with the surfaces of the corresponding projections on member A when the mem bers are placed in assembled relation without any fusible material between the adjacent surfaces thereof, yet it is preferable, es-: pecially when the members are formed from sheet metal or the like, to form each indentation by means of suitable dies adapted to bend out a portion of the metal from the bodyof the member into a sort of V having an angle of substantially 90 degrees between its interior adjacent faces when the projections on member A are formed as hereinbefore described, or other suitable angle corresponding to the angle formed by the sides of the projections in'case the angles of these projections be varied from those employedin the preferred embodiment of the invention, each indentation beingofa suitable size to fit over and contact with the'outer surface of its corresponding projection on member A when the members are brought together into assembled relation without any fusible metal between their adjacent faces. In practice, it is preferable to formthe projections very slightly narrower than the corresponding indentations in orderthat a slight clearance maybe provided between the edges of the projections and the adjacent portions of membersB and C when the link is assembled in order to permit thereadyseparation of theparts-of the link' in operation.

The bodies of members B and C are each provided with suitable apertures 14, 14 disposed adjacent that end of each body farthest from the indentation or indentations therein, these apertures being arrangedto come into substantial alinement with each other when the link is assembled to afford means whereby the-link may be engaged by, one of the arms of the sprinkler head, or the like, to which it is attached when in use as shown in Fig. 1. V

The various members of the link, having been formed hereinbefore described, may be assembled in the position shown in Figs. 1 and 2; that is with theprojection 3 engagingin indentation 9 and projections 4t, 4; engaging .in indentations 12, .12, sultablcfusible metal 15 beingrdisposedbetween the adjacent facesof the members tonormally unite them togetherasv will be readily un-= derstood by thosefamiliar with the art; Inthis positionthat end of member. A having aperture 6 will extend beyond the adjacent ends-of members B and O, andin a corresponding" manner the ends-of members B and C having; apertures 14L- willv extend beyond-the'adjacent end of member A to permit the. ready attachment of the link to the arms of thesprinkler head or to other .ap:- paratus with which it is intended to co-- operate.

When the link isattached to a sprinkler" head as shown inl ig; 1, solongas the temperature in the vicinity thereof remains be low the fusing point of the material 15 the members of the link will remainin positive assembled relation, being held in that/position by the fusible materialbetween theiradjacent faces. It will be evident that in their assembled position the several 111cm hers-of thelink will each present a large surface for contact with the fusible matef rial, and that thelatter-,moreover, will be relieved of a large 'p a-rt of the strainer;- erted'by the arms of the sprinkler head by reason of the mutual engagement of I the several projections and indentations with which the members of the link are provided so that, in fact, theduty of the 'fusiblematerial= is substantially reduced to thatof merely holding themembers together. In consequence, -relative movei'nent or creeping between the members is avoided even thouglr the link may bekeptunder heavy'strain for longperiods of'timeprovided that the tem perature of the surrounding atmosphere remains belowthe fusing point of the fusible material. When the temperature in the vicinity? of the link, however, risesto a point sufficient to melt the fusible material; the strain exerted by the lever arms or other devices to which the link is attached causes a relative longitudinal movement of the member "A, and members B and C which; inturn, forces membersB and C laterally outward =as thestruok-up portions 3 anda; 4 of memberA move longitudinally with respect to members 3 and C, thus movingboth of the latter away from member A Witlwa rwedging action -andresulting in' a positive and substantially instantaneous relative separation of all of the members to release the lever arms of the sprinkler head or other device to which the link may be attached.

It will be evident that a very slight relative longitudinal movement of the members will result in forcing the outer members B and C away from the intermediate member A for a relatively considerable distance so that the water issuing from the sprinkler head and striking the members of the link will not serve to prevent their positive separation by chilling the fusible material between their adjacent surfaces after it has once fused, but that, on the contrary, as

soon as the fusible material melts sufficiently with mechanisms having parts normally tending to move toward each other instead of to separate, and that when used in connection with such mechanisms the link, while normally under longitudinal compression instead of tension, will serve equally well to maintain the movable parts to Which it is attached in fixed relation until the fusing of the material 15 when the members of the link will positively and promptly separate to permitthe parts to which they have been attached to move toward each other to effect the purposes of the device. vVhile I have herein illustrated and described a preferred embodiment of my invention with considerable particularity, I do not desire or intend to thereby limit myself specifically thereto, as it will be evident that various changes and modifications may be made inthe details of construction and arrangement of the various parts, and the relative proportions thereof may be varied as desired, and that members having projections and corresponding indentations differing in number from those herein illustrated and described may be employed, Without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention I claim and desire to protect by Letters Patent of the United States 1. A fusible link comprising an intermediate member having a body and a single projection extending outwardly from one side thereof equidistant from the lateral edges of said body and a pair of projections extending outwardly from the other side thereof adjacent the lateral edges of said body, and a pair of exterior members,

one of said members having a single indentation adapted to receive said first-mentioned projection and located equidistant from the lateral edges of said member and the other of said members having a pair of indentations adapted to receive said lastmentioned projections and located adjacent the lateral edges of said member, said indentations extending in a single direction from the planes of the bodies of their re spective members.

2. A fusible link comprising an intermediate member having a body and alined projections extending outwardly therefrom, one of said projections extending from one side of said body and equidistant from the lateral edges thereof, and the other projections extending from the opposite side of said body adjacent the lateral edges thereof, and a pair of exterior members respectively indented in a single direction, one of said members having an indentation adapted to receive said firstmentioned projection and positioned equidistant from the lateral edges of said member, and the other of said members having a pair of indentations each adapted to receive one of said last-mentioned projections each positioned adjacent the lateral edges of said member, and fusible material between the adjacent surfaces of said members operative to maintain said members in operative relation.

In witness whereof I have hereunto set my hand this 19th day of July, A. D. 1916.

' LEROY M. LEWIS. Witnesses:

GEORGE K. HELBERT, ALEXANDER PARK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.? 

